1. Field of the Invention
This invention relates in general to an apparatus and processes utilizing the apparatus, more particularly to a vessel for chemically or biologically treating flowable materials and processes therewith.
2. Description of the Related Art
It is common in various manufacturing and remediation processes to chemically react or biologically alter flowable materials such as liquids or sludges to form products for use, further processing, or disposal. These flowable materials may contain environmentally undesirable compounds, or pollutants. For example, many organic compounds are directly regulated by the Environmental Protection Agency (EPA) and/or adversely effect the chemical oxygen demand (COD) and/or biological oxygen demand (BOD) levels in rivers, streams, lakes, ponds, harbors, oceans and/or underground water reservoirs into which they enter. Many of such materials may not be permitted to be discharged directly into the environment making it advantageous to treat such materials onsite.
Often times the flowable materials to be reacted or treated contain a high amount of solids, for example manure. These sludges become difficult to mix and biologically treat or chemically react in traditional tanks or vessels. Traditional tanks or reactor vessels typically are in the shape of cylinders, or have a configuration with a larger volume in a lower portion of the vessel. Vessels of the prior art typically have a low flow rate in a lower portion of the vessel causing a higher amount of solids to settle or accumulate in the bottom of the vessel. The settling of solids in the tank, especially during system shutdown, makes it difficult or costly to restart or mix the entire contents of the vessel to eliminate dead spots or no-flow volumes within the vessel. The dead spots in the vessel result in slow or no treatment or reaction of the accumulating solids and reduce the usable volume of the vessel.